klaassen etal



Oct. 31, 1961 H. KLAASSEN ETAL 3,006,419

APPARATUS FOR ADJUSTING THE PITCH OF THE BLADES OF A MARINE PROPELLER Filed Jan. 11, 1960 v 2 Sheets-Sheet 1 FIG.

INVENTORS BY 7W ATTORNEY 001:. 31, 1961 H. KLAASSEN ET AL 3,006,419

APPARATUS FOR ADJUSTING THE PITCH OF THE BLADES OF A MARINE PROPELLER Filed Jan. 11, 1960 2 Sheets-Sheet 2 ATTORNEY United States Patent 3,006,419 APPARATUS FOR ADJUSTING THE PITCH 0F 7 THE BLADES OF A MARDIE PRGPELLER Hendrik Klaassen, Drunen, and Willem Daane, Vlijmen,

Netherlands, assignors to Lips N.V., Drunen, Netherlands, a corporation of the Netherlands Filed Jan. 11, 1960, Ser. No. 1,468 Claims priority, application Netherlands Jan. 12, 1959 7 Claims. (Cl. 170160.32)

This invention relates to apparatus for adjusting the pitch of the blades of a marine propeller.

Many kinds of apparatus for this purpose are known. In some known apparatus a servomotor cylinder is formed by a widened hollow part of the propeller shaft, in which a piston, the piston rod of which is immediately connected to or integral with the control rod, is movable axially therein by admitting hydraulic fluid to one or the other side of the piston.

These known apparatus suffer from the inconvenience that repairs and replacements are dilficult and are only possible by handling and machining large and heavy parts.

Many other proposals have been made in this field of the art, several of them not showing the above inconveniences, but in the latter cases they show other disadvantages, often show a lack of reliability and are often very complicated and expensive. Complicated and sometimes vulnerable means for transmitting axial movements and forces from stationary rotating parts are often necessary.

The present invention has for its object to attain a simple and reliable structure, also for large diameter propeller shafts, of an apparatus as indicated in the preamble.

To achieve this object an apparatus for adjusting the pitch of the blades of a marine propeller according to this invention comprises a hollow propeller shaft, a control rod within said shaft and axially movable with respect thereto, to adjust the pitch of the blades, a servomotor, comprising a number of cylinders with pistons and piston rods extending along the outside of the propeller shaft and at least approximately equally divided along the periphery of said shaft, one part of which cylinders and piston rods being connected to the outside of the shaft so as to rotate therewith but so as to be immovable with respect thereto in the axial direction, the other part of said cylinders and piston rods being connected to said control rod for moving it axially upon actuation of said cylinders and pistons.

This makes it possible to apply as servomotor units hydraulic cylinders with pistons of a standard kind and size immediately and to be in many ports of the world commercially available. Moreover the structure is quite reliable and simple. The ships engineers are able to replace cylinders in a less difficult manner. Moreover if one cylinder fails the others will continue administering an adequate adjustment of the pitch, so that stopping of the ship is unnecessary.

The invention moreover includes features which are further embodiments of the above given characteristics and which will be clear from the annexed claims.

The invention will now be explained in more detail with reference to the annexed drawings, which by way of example only give a preferred embodiment of an apparatus according to the invention.

In the drawings:

FIG. 1 is a longitudinal vertical section through the axis of a portion of the propeller shaft.

FIG. 2 is a longitudinal vertical section through the axis of a further portion of the propeller shaft which is a continuation of FIG. 1.

The propeller shaft is indicated by 1 and is hollow at the side close to the propeller (left side in the drawing),

3,885,419 Patented Oct. 31, 1961 a control rod 2 passing therethrough. This left part of the propeller shaft has a flange 3, through which the shaft joins a wider hollow cylindrical part 4, which at its other end is connected to a flange 5 of a part 6 of the shaft. The parts 3, 4 and 5 constitute a casing 7 and the control rod 2 at its inboard end carries a disc 8 arranged in this casing.

The shaft part 6 has a conical surface 9, upon which an annulus 10 has been secured by a nut 11. The disc 8 and the annulus 10 carry at a number of positions equally divided along the periphery of the shaft sets of two lugs 12 and 13 respectively. In the flange part 5 openings 14 have been provided each exactly with their axes between each set of adjacent lugs 12 and 13. Through each opening 14 a piston rod 15 of a double acting hydraulic servomotor unit with a cylinder 16 extends, embodied as a unit of standard type and dimension commercially available in many parts of the world. The cylinder 16 engages at its back or right end pivotally the corresponding set of lugs 13 and the piston rod engages pivotally the corresponding set of lugs 12 with its free end.

Within the casing 7 there is moreover arranged an electrically operated hydraulic selecting valve 17. Within the central hollow space in the part 6 of the shaft bordering the casing 7 a pressure vessel 18 is provided, embodied as a hydro-pneumatic pressure-accumulator, so that it has a gas space which is elastically compressed and exents pressure upon a hydraulic fluid present therein.

At the right end of shaft part 6 a sleeve 20 is provided upon a conical surface 19 and secured thereon by a nut 21. The sleeve 20 has a flange, through which it joins to a hollow cylindrical part 22, which at its other end joins a flange 23 of the part of the propeller shaft 1 shown at the right end of FIGURE 2. The parts 20, 22 and 23 together constitute a chamber 24, in which a pump 25 is provided. This pump is supported by a conical support 26, which is secured with its base to an edge of the sleeve 20. A friction coupling 27 is provided upon the shaft of the pump rotor within the support 26. On the part of said shaft positioned more to the left, a double pulley 28 for V-belts is arranged.

An oil reservoir mounted in the ship above the shaft and indicated by 29 has a connection 30 to an annulus 31 mounted around the propellershaft part 6. Sleeve seals 32 and a ball bearing 33 are mounted in said annulus 31, so that the annulus is supported by the propeller shaft, but said annulus is nevertheless maintained stationary during rotation of said shaft, e.g. by a suitable embodiment of duct 30. An oil chamber 34 in said annulus 31 is in communication with a long axial oil passage 35 extending through the entire propeller shaft part 6. At the right end this passage is in connection with the suction side of the pump 25 through a pipe 36 and at the left end a duct 37 connects this passage to the discharge opening of the selector valve 17. From the pump a pressure discharge duct 38 for the oil put under pressure in said pump extends through a check-valve 38a to a central bore 39 in shaft part 6, said bore branching oif into a passage to the accumulator 18 and a bore 40, leading through the duct 41 to the entry opening of the selector valve 17. From the bore 39 a further bore 42 branches off to a chamber 43, closed at one end by a diaphragm. This diaphragm operates a rod 44 for coupling and discoupling the friction coupling 27. The diaphragm is influenced by a snap ball 45 acting upon the rod thereof. This ball co-operates with two recesses or narrowed parts in the rod 44 for stopping this rod in two positions as shown, namely in a position for connecting coupling 27 and in a position for disconnecting coupling 27. The ball 45 is urged towards the rod 44 by a spring 46, the pressure of which is adjustable by an adjusting screw 47.

An electric lead 48 leads to a number of brush conmaintained in the correct position when the pitch differs rom the adjusted value thereof, whereas when the pitch isequal to the adjusted value thereof no electrical impulse is given anymore, so that the selector valve 17 automatically returns to the centralposition in which no oil supply and no oil discharge to and from the servomotor units 16 can occur.

The pulleys 28 are connected byV-belts 50 to two pulleys 51 of a set of four pulleys embodied as an integral body and mounted for rotation upon a trunnion 52 at the outer end of an arm 53 being integral with or secured to the sleeve 20. I I

The two pulleys 54 of said integral body are connected by fV-belts 55 to an annulus 56 with two V-belt grooves; said annulus being mounted stationary around the cylindrical part 22 of the chamber 24 and the support of this annulus has been shown only diagrammatically in the drawing as by brackets 57. I Ducts 53, bores 59 and ducts 6t} connect the selector valve 17 to both sides of the hydraulic servomotor cylinders 16. g

A safety overflow valve 61 connects the passage 39 to the passage 35. b V

The operation of this apparatus is as follows: 7

With rotation of the propeller shaftthe casing of the pump 25 rotates together therewith with the same annular speed. Through the annulus 56, the pulleys 51 and 54 and the pulleys 28 with the V -belts between said parts, the rotor of the pump is rotated relative to the casing thereof and thus oil, which is allowed to flow from the Mi i i ul h Pitch di me t oul b? derived from a manually operated adjusting device for the pitch or from an automatic control device. By a follow-up connection the electric impulse could be interrupted as soon as the adjusted pitch is attained.

What we claim is: L I

1. Apparatus for adjusting the pitch of the" blades of a marine propeller comprising a hollow ropeller shaft, a control rod within said shaft and axially movable with respect thereto to adjust the pitchof the'blades,

a servomotor comprising a number of units having a first part and a second partextending around the outside of the propeller shaft and at least approximately equally reservoir 29 through the duct 30 to the passage 35, is put under pressure by the pump and is discharged under pressureinto the bore 39. The pressure of this oil also be increased in the accumulator 18 and is influenced by the gas pillow therein, and said pressure is alsoincreased at one side of the selector valve 17. Now, if it is necessary to vary the pitch of the propeller blades, an electric impulse is given through the lead 48 and the brush contacts 49 to the electrical part of the selector valve 17, which thus takes up the desired position. Oil under pressure flowing through passage and duct 41 to the selector valve is thus passed by said valve to that side of the servomotor units 16 which gives a displacementof the pistons therein in the desired direction. With such a displacement the piston rods 15, the lugs 12 and the disc 8 are also displaced-and the disc '8 entrains the control rod 2 in this movement. If it is necessary to stop the adjusting movement of the pitch the electric impulse through lead 48 is interrupted, the slide valve or other movable part of the selector valve 17 returns to the central posi tion and thus this valve does not transmit more oil to the cylinders 16, so that the control rod is not moved anymore. During the pitchadjusting movement the oil flows from the low pressure side of the pistons in the cylinders 16 throughthe corresponding ducts 60, bores 59 and ducts 58 and through the selector valve 17 to the duct 37 and to the passage 35 back to the pump. b If no pitchadjustment has to take l'ace the pump 25 continues the pumping, the oil cannot flow in the above described manner past the selector valve 17, the oil pressure will thus rise and thus this pressure acting through passage 42 on the diaphragm in the chamber 43 will move this diaphragm outwards and will thfisthrough rod 44 disengage the friction coupling 27, so that the pump rotor is not driven. The check valve 38a now maintains the accumulator 18 andthe passages for the oil to the selector valve 17 filled and under pressure. As an additional safety measure the safety valve 61 operates if necessary to allow the oil from the passage 39 to escape to the passage 35 if the pressure would become too high.

divided around the periphery of said shaft, said first part being connected to the outside of the shaft, a casing having a radial end wall provided openings formed as a widened part of the propeller shaft a yoke disposed in said casing and being connected to the said control rod, said second part extending through one of said openings insaid radial end wall and engaging said yoke, and means to actuate said servornotor. V w

2. Apparatus for adjusting the pitch of the blades of a marine propeller comprising a hollow propeller shaft, 21 control rod within said shaft and axially movable with respect thereto to adjust the pitch of the blades, a servomotor comprising a number of cylinders with pistons and piston rods extending around the outside of the propeller shaft and at least approximately equally divided around the periphery of said shaft, said cylinders and piston rods having a part, connected to the outside of the shaft so as to rotate therewith but so as to be immovable with respect thereto in the axial direction and another part connected to said control rod for moving it axially upon actuation of said cylinders and pistons, a pump for putting a hydraulic fluid under pressure, and a selecting valve for controlling the supply of said fluid to the servomotor being mounted on the propeller shaft for rotation therewith.

3. The I apparatus of claim 2, further comprising a stationary annulus mounted around the propeller shaft having a space therein, said annulusengaging said shaft in a sealing manner and connected to a supply of hydraulic fluid under low pressure, a passage con nected to the shaft for transmitting said fluid from the space within said annulus and guiding it to the 4; The apparatus of claim 2, wherein the pump is arranged a chamber in" the propeller shaft; transmis-' sion means engaging a stationary annulus being mounted around the shaft for driving the driven part of the pump by a relative movement thereof with respect to the non-driven part of the pump, as said shaft is rotated.

5. The apparatus of claim 4, wherein said tra'nsmission means comprises a flexible endless transmission member engaging about said stationary annulus and a first pulley rotatable upon an arm protruding from the propeller shaft, and a further flexible endless" trans-' mission member engaging about a second'pulley fixed to said first pulley and a driving pulley mounted on said pump; U h 6. The apparatus according to claim 1, wherein said means comprises a pump for pumping a supply of hydraulic fluid, and a selecting valve for controlling the-- supply of hydraulic fluid to the se'rvomotor.

, 7. The apparatus according to claim 6, wherein a hydropneum-atic pressure accumulator is provided centrally in a cavity of the propeller shaft and is connected to said pump.

References Cited in the file of this patent UNITED STATES PATENTS 2,149,388 Caldwell Mar. 7, 1939 2,501,617 Roesch ;.V V Mar. 21, 1950 2,653,669 Moore Sept. 29, 1953 g FOREIGN PATENTS V J v v I 588,795 Great Britain June 3, 1947' 

